iStock/Thinkstock (file photo)(NEW YORK) -- NASA is downplaying a prediction by Ukrainian scientists that a massive asteroid named 2013 TV135 will hit Earth 19 years from now.

A potential strike by the giant rock is not a threat to take lightly but this 1,300-foot wide asteroid has a less than .0021 percent chance of hitting the planet in 2032, says NASA's Dr. Paul Abell. That's about a one in 48,000 chance and Abell believes it will shrink to zero.

Although hundreds of tons of space junk fall back to Earth every day, most of it so small to be noticed, it's the big stuff that worries scientists.

Abell admits Russian scientists have good reason to be sensitive. The 55-foot-wide asteroid that hit in Chelyabinsk last February with no warning sent out a blast equivalent to 440 kilotons.

The last huge asteroid to smash Earth before Chelyabinsk was one that slammed into Tunguska, Siberia, in 1908, devastating a thousand square miles of rural Siberia.